[function] moved VisualizationAdapter from default to visualization
[functions.local] removed
[test.test_common] fixed includes and fem namespaces
[functions.interfaces] added possibility for checks
[functions.constant] added checks
[functions.expression.base] restructuring

Removed all eigen dependencies and moved
FunctionExpressionBase to Function::MathExpressionBase
[functions.expression] major refactoring

To get the same as before, but in the new layout.
[functions] disabled all but the working ones for the moment
[autotools] whitespace